Summernote doesn't call the onChange callback when changes are
done in the code mode, so the html field isn't aware of those
changes. It means that if the user does some changes in code mode
and then save directly (without coming back to normal mode), those
changes are lost.
This rev. ensures to save every changes by manually come back to
the normal mode before saving, as this will correctly trigger the
changes. Actually, it simply restores some code of the previous
implementation (before new views) of this widget.